Conventional hot-melt carpet seaming tape for joining abutting edges of carpet has long been on the market. Illustrations of such tape are disclosed fully in the U.S. patents to Burgess, U.S. Pat. No. 3,400,038, issued Sept. 3, 1968, and Clymin, U.S. Pat. No. 3,485,704, issued Dec. 23, 1969.
Such conventional hot-melt seaming tape usually has a backing of paper with a layer or layers of heat sensitive adhesive adhered or otherwise secured to the paper. In conventional use in face seaming two segments of carpet are laid on a floor or other supporting surface with edges of the segments abutting with the joint line between the segments in approximate registry with the centerline of a length of such tape laid beneath the carpet. A hot electric iron is then passed along the tape between and under the abutting edges of the carpet and in contact with the adhesive of the tape to melt the same, the tacky adhesive sticking to the bottom or backing of the carpet segments to adhere the segments to the tape and indirectly to each other through the tape to provide an almost invisible seam between the carpet segments.
Electric irons for such carpet seaming are disclosed in the U.S. patents to Burgess, U.S. Pat. No. 3,400,245, issued Sept. 3, 1968, and Hill, U.S. Pat. No. 3,523,176. Such method of face-seaming carpet is disclosed in said patents as well as the U.S. patent to Burgess, U.S. Pat. No. 3,415,703, issued Dec. 10, 1968.
In such face seaming of carpet with such conventional seaming tapes and irons, it is very important to correctly align the tape with the joint between the carpet segments, to align the iron relative to the tape and joint, and to maintain them in such alignment during movement of the iron along the tape to insure that the adhesive on the tape is melted uniformly and is about equally applied to each carpet segment, to form the most effective joint between the segments. Difficulty is usually experienced in doing so because the tape tends to slide laterally on the floor or other supporting surface and the iron tends to slide laterally on the tape. The operation is complicated by the fact that the tape and most of the iron are covered by the carpet segments in face seaming, and proper alignment can be maintained only by parting the carpet segments frequently and visually correcting any misalignment, which is undesirably time consuming and does not assure correct alignment in subsequent movement of the iron. Most of such hot-melt carpet seaming tape sold commercially is provided with a visible center guide line to assist in such visual alignment, but is of little assistance to the mechanic in maintaining alignment during movement of the iron along the tape.
The U.S. Pat. No. 3,582,436, to Bucher, issued June 1, 1971, describes some of the difficulties involved in maintaining alignment of hot-melt seaming tape and the joint between abutting carpet edges to be seamed, and describes a specially designed electric iron for allegedly accomplishing such alignment. My experiments, however, have indicated that the results claimed by the Bucher patent for its electric iron will not, at least with any assurance or regularity, be attained in normal use to maintain such alignment.